Apparatus for burning pulverized fuel



c. P. CRAWFORD APPARATUS FOR BURNING I ULVERIZED FUEL Mar, 13, 1923. 1,448,390

F 11ed Au 25, 1919 (7%?1452 fimgmz and State of Utah,

' the heatoutput of even Patented Mar. 13, 1923.

inane CHARLES P. CRAWFORD, OF SALT LAKE CITY, UTAH.

APPARATUS FOR BURNING PULVERIZED FUEL.

Application filed August 2 5, 1919. Serial No. 319,531.

T all whom it may concern Be it known that I, CHARLES P. CRAWFORD, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake have invented certain new and useful Improvements in Apparatus for Burning Pulverized Fuel, of which the following is a specification.

This invention has reference to means for the utilization of finely comminuted fuel as a heating agent whereby, among other advantages, the necessity of the preheating of the fuel, and the necessity of using an excessively large volumeof air of combustion, or of equivalent means, aredispensed with.

i It is one ofthe objects of my invention to utilize the well-known gas-condensing and absorbing, and to some extent catalytic action of finely divided combustible matter, such as coal dust for instance which, when moist is liable to spontaneouscombustion, as a means of generating a high degree of heat without the inconvenience resulting from preheating thereof, and from the use of high-power blasts for blowing the material into a large space and mixing it with a large volume of oxygen or air of combustion.

Another object of my vide efficient means of invention is to progreatly increasing inferior grades of comminutable fuel, and" incidentally toincrease the efficiency of closed or open containers heated by such fuel, and to minimize and eliminate the dangers otherwise connected with the useof such fuel.

Other objects and. advantagesof my invention will appear from the following detailed description thereof, and from its illustration in the accompanying drawing.

In the accompanying drawing I have represented a preferred form of carrying my invention into effect as applied to an ordinary boiler provided with a heating furnace, the parts being shown partly in elevation and partly in section, but it is understood that my invention is'not limited to the particular casual practical application shown in the drawing, but in its broader aspects comprises the various means and instrumentalities set forth in the claims.

In the drawing: 1 shows a conventional form of boiler; 2 is the brickwork of the furnace masonry provided with the customary fire doors, and ash doors conventionally indicated on the drawing; 3 is the' baffle or fire bridge wall from which a flue surrounding the rear thereof; 4 1s a water leg,'provided with a longer leg 5, and a shorter leg 6, which latter is preferably arranged near the front part of the boiler; 7 is a chute or feeding tube connected to the coal supply, not shown in the drawing, and leading into the hopper 8. is a mixing tube or the like, projectingthrough the brickwork 2 into the interior of'the' furnace, any suitable part of which is mounted within the interior of the water leg 4. 16 is a nozzle at the free' end of thetube or chamber 15, projecting through the wall of the tubeor water leg 4, and preferably directed toward the front part of the boiler. v

The tube or chamber 15 communicates with the bottom partof the hopper 8, a feed screw 9, or similar means being arranged within the hopper at or near-its juncture with the chamber ortube 15. 10 is the driving shaft for the feed screw 9, the shaft being connected to a source of "motion by means, not shown in the drawing 13 is a steam connecting pipe establishing communication from the boiler with the chamber or tube 15, preferably in front'of the fuel delivery means; 11 indicates diagrammatically a steam injector, controlled by valve mechanism 14, of which 12 is the shut-off and steam-admitting valve orthe like.

The herein-described instrumentalities opcrate as follows :The finely disintegrated fuel, coal-dust for instance, is intimately mixed with steam inthe mixing chamber 15, which is protected against radiation of heat by its being surrounded by the water leg 4. Owing to the condensing and catalytic action of the coal dust a large amount of the steam is dissociated very much below the dissociation temperature of water, carbon inonoxid and hydrogen being some of the products of the reaction with coal dust similar to the formation .of water gas. A strong draft being created at the discharge nozzle or nozzles 16 by outside air, not shown in the drawing, or otherwise, the gaseous highly combustible products of the reaction are immediately carried off, the combustible miX- ture escaping from the nozzle or nozzles being partly gaseous so that a substantially part of the boiler extends to complete smokeless combustion is obtained,

the device acting as a continuous gas producer, effecting the combustion by means of hydrocarbons and water vapor, a complete combustion being thus obtained almost instantaneously.

The steam is employed either as saturated or superheated steam. The reaction is assisted by the provision of the water leg 4, which receives the heat directly fronrthe gases ascending from the'nozz1e or nozzles 16, or reflected from the walls of the furnace, and the upwardly and forwardly inclined arrangement of the water leg 4:, is particularly advantageous because by this means a long flame is produced, and the flame with the assistance of outside air admitted through a grate or'the like, as above described, flows substantially parallel with the slope of the water leg l, and is uniformly in contact for its entire length with said water leg. The water leg also causes the boiler water to circulate freely, which is very desirable. At the same time a temperature is maintained in the mixing chamber 15, substantially equal to the temperature of the steam when it strikes the pulverized coal, and the flame in the form of construction shown in the drawing is projected towards the fire door and away from the lines. The type here shown as an instance of carrying my invention into effect, will be desirable for locomotive burners.

My invention may be employed in combination with various forms of heating and burning devices, and it may be applied to all kinds of open or closed containers in which the temperature of the contents thereof are raised, and the vapor or steam upon the inntual reaction of which thefinely distlnteg rated fuel my invention depends may be generated in any suitable manner. Various other modifications and means of application and utilization of'my invention will suggest itself to the expert in accordance with the necessities of local conditions, my invention not being confined to any particular forms of realization thereof except as appears from the claims hereunto appended.

\Vhile I have shown my invention as supplied with one chamber 15 and one by-pass l, it is obvious that a plurality of such bypasses, and a plurality of mixing chambers 15 having nozzles 16, may be used. In such case the arrangement may be similar to that of the superheater tubes in locomotive boilers. Also the inclination of the bypass 4 may be changed, the by-pass being, for instance, parallel to the boiler.

What I claim is l 1. In a heating and burning device, the combination with a boiler and a furnace chamber surrounding part of said boiler, of forwardly inclined tubular liquid circulating means at the outside of the boiler and communicating therewith within said. oh amber, fuel delivery means leading from the outside into the interior of said liquid circulating means and projecting therethrough into said chamber, fuel supplying means at the outer end of said delivery means and communicating therewith, and means for leading vapor from the boiler to said delivery means adjacent said fuel supplying means. l

2. An apparatus for burning pulverized fuel, consisting of a furnace, a boiler above said furnace, a water leg depending from the boiler into said furnace. a fuel feeding pipe extending from the outside of the furnace into said water leg and coaxially therewith for a portion of its length, and through the wall thereof into the furnace, a discharge nozzle secured to the inner end of said pipe, a fuel supply hoppercommunicating with said pipe, a feed chute leading to said hopper, a feed screw in said hopper, and steam injecting means leading from the boiler to the fuel feeding pipe.

In testimony whereof I aiiix my signature in the presence of two witnesses.

GAMILLA 'MAsoN, H. E. HENDERSON. 

